1. Field of the Invention
The proposed technical solution relates to a field of measuring means and devices and can be used for more accurate measuring of the volume flow rate of a controlled medium in a pipeline.
2. Description of Related Art
Similar technical solutions are known, e.g. see Russian Federation patent No. 2160887, IPC: G01F 1/66. The prior art publication contains:                a pipeline with a controlled medium;        a first transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium;        a second transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium and shifted in relation to the first transmitting-receiving radiator of ultrasonic signals;        a multiplexer whose first and second in-ports are connected to the out-ports of the first and the second transmitting-receiving radiator of ultrasonic signals, respectively;        an amplifier of ultrasonic signals whose in-port is connected to the out-port of the multiplexer;        a comparator whose first in-port is connected to the out-port of the amplifier of ultrasonic signals;        an OR-circuit whose first in-port is connected to the out-port of the comparator;        a first univibrator whose in-port is connected to the out-port of the OR-circuit;        a first AND-circuit whose first in-port is connected to the out-port of the first univibrator;        a second univibrator whose in-port is connected to the out-port of the first univibrator;        a second AND-circuit whose first in-port is connected to the out-port of the first univibrator;        a first source of ultrasonic signals whose in-port is connected to the out-port of the first AND-circuit, and whose out-port is connected to the in-port of the first transmitting-receiving radiator of ultrasonic signals;        a second source of ultrasonic signals whose in-port is connected to the out-port of the second AND-circuit, and whose out-port is connected to the in-port of the second transmitting-receiving radiator of ultrasonic signals;        a third AND-circuit;        a counter of impulses whose first in-port is connected to the out-port of the third AND-circuit, and whose out-port is connected to the first in-port of the third AND-circuit;        a successive code approximation register whose first in-port is connected to the out-port of the counter of impulses;        a subtracting unit whose first in-port is connected to the out-port of the successive code approximation register;        a digital-to-analog converter whose in-port is connected to the out-port of the subtracting unit, and whose out-port is connected to the second in-port of the comparator;        a microprocessor-controlled control driver whose first out-port is connected to the second in-ports of the first and the second AND-circuits and to the third control in-port of the multiplexer, whose second out-port is connected to the second in-port of the OR-circuit, to the second in-port of the counter of impulses, and the third in-port of the successive code approximation register, whose third out-port is connected to the second in-port of the successive code approximation register, whose fourth out-port is connected to the second in-port of the subtracting unit, whose first in-port is connected to the out-port the of successive code approximation register, and whose second in-port is connected through a bidirectional bus to the third in-port of the comparator, to the out-port of the second univibrator, and to the second in-port of the third AND-circuit;        a microprocessor-controlled unit for computing the time of ultrasonic signal transmission in the direction of the flow of the controlled medium in a pipeline;        a microprocessor-controlled unit for computing the time of ultrasonic signal transmission counter the direction of the flow of the controlled medium in a pipeline;        a microprocessor-controlled unit for computing the time difference between ultrasonic signal transmission in and counter the direction of the flow of the controlled medium in a pipeline;        a microprocessor-controlled unit for determining (computing) the volume flow rate of the controlled medium in a pipeline.        
The proposed technical solution and the above-described similar prior art technical solution are characterized by the following common features:                a pipeline with the controlled medium;        a first transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium;        a second transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium and shifted in relation to the first transmitting-receiving radiator of ultrasonic signals;        a multiplexer whose first and second in-ports are connected to the out-ports of the first and the second transmitting-receiving radiator of ultrasonic signals respectively;        an amplifier of ultrasonic signals whose in-port is connected to the out-port of the multiplexer;        a source of ultrasonic signals;        a digital-to-analog converter;        a control driver whose first out-port is connected to the third control in-port of the multiplexer;        a unit for computing the time of ultrasonic signal transmission in the direction of the flow of the controlled medium in the pipeline;        a unit for computing the time of ultrasonic signal transmission counter the direction of the flow of the controlled medium in the pipeline;        a unit for computing the time difference between ultrasonic signal transmission in and counter the direction of the flow of the controlled medium in the pipeline;        a unit for determining (computing) the volume flow rate of the controlled medium in the pipeline;        
A different prior art technical solution (see USSR Inventor's Certificate No. 918790) is believed to be the closest analog to the claimed solution. It contains:                a pipeline with the controlled medium;        a first transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium;        a second transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium and shifted in relation to the first transmitting-receiving radiator of ultrasonic signals;        an ultrasound signal source made as a lockable self-excited oscillator, delay unit whose in-port is connected to the out-port of the lockable self-excited oscillator, and a high-voltage pulse driver whose in-port is connected to the out-port of the delay unit, the first out-port of the ultrasound signal source being connected to a pin of the first transmitting-receiving radiator of ultrasonic signals while its second out-port being connected to a pin of the second transmitting-receiving radiator of ultrasonic signals;        a first multiplexer whose first in-port is connected to the pin of the first transmitting-receiving radiator of ultrasonic signals;        a first control unit whose out-port is connected to the second, control, in-port of the first multiplexer;        a second multiplexer whose first in-port is connected to the pin of the second transmitting-receiving radiator of ultrasonic signals;        a second control unit whose out-port is connected to the second, control, in-port of the second multiplexer;        a first ultrasonic signal amplifier whose in-port is connected to the out-port of the first multiplexer;        a first unit for converting ultrasonic signals into square pulse packets that correspond to the time of ultrasonic signal transmission in the direction of the flow of controlled medium in the pipeline, whose in-port is connected to the out-port of the first ultrasonic signal amplifier;        a unit for computing the time of ultrasonic signal transmission in the direction of the flow of controlled medium in the pipeline, made as a first sampling unit whose in-port is connected to the out-port of the first unit for converting ultrasonic signals into square pulse packets;        a second amplifier of ultrasonic signals whose in-port is connected to the out-port of the second multiplexer;        a second unit for converting ultrasonic signals into square pulse packets that correspond to the time of ultrasonic signal transmission counter the direction of the flow of controlled medium in the pipeline, whose in-port is connected to the out-port of the second ultrasonic signal amplifier;        a unit for computing the time of ultrasonic signal transmission counter the direction of the flow of the controlled medium in the pipeline, made as a second sampling unit whose in-port is connected to the out-port of the second unit for converting ultrasonic signals into square pulse packets, and whose out-port is connected to the in-port of the lockable self-excited oscillator of the ultrasonic signal source;        a unit for computing the delay time difference between ultrasonic signals transmitted in and counter the direction of the flow of the controlled medium in the pipeline, whose first in-port is connected to the out-port of the unit for computing the time of ultrasonic signal transmission in the direction of the flow of controlled medium in the pipeline, and its second in-port is connected out-port of the unit for computing the time of ultrasonic signal transmission counter the direction of the flow of controlled medium in the pipeline;        a modulation pulse generator whose in-port is connected to the out-port of the first unit for converting ultrasonic signals into square pulse packets;        a first demodulator (low-pass filter) whose in-port is connected to the out-port of the unit for computing the delay time difference;        a modulator whose first in-port is connected to the out-port of the modulation pulse generator and whose second in-port is connected to the out-port of the first demodulator;        a second demodulator (low-pass filter) whose in-port is connected to the out-port of the modulator;        a scaling amplifier (a unit for computing a signal proportional to the controlled medium flow rate in the pipeline) whose in-port is connected to the out-port of the second demodulator (low-pass filter).        
The claimed technical solution and the above-described similar technical solution believed to be the closest analog to the claimed one are characterized by the following common features:                a pipeline with the controlled medium;        a first transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium;        a second transmitting-receiving radiator of ultrasonic signals installed on the pipeline with the controlled medium;        a source of ultrasonic signals;        a first multiplexer;        a second multiplexer one of whose in-ports is connected to the pin of the second transmitting-receiving radiator of ultrasonic signals;        a control driver (control unit) whose first out-port is connected to the third, control, in-port of the second multiplexer;        an amplifier of ultrasonic signals whose in-port is connected to the out-port of the second multiplexer;        a unit for computing the time of ultrasonic signal transmission in the direction of the flow of the controlled medium in the pipeline;        a unit for computing the time of ultrasonic signal transmission counter the direction of the flow of the controlled medium in the pipeline;        a unit for computing the time difference between ultrasonic signal transmission in and counter the direction of the flow of the controlled medium in the pipeline;        a unit for determining (computing) the volume flow rate of the controlled medium in the pipeline.        
The technical result that cannot be achieved with any of the above-described prior art technical solutions consists of decreasing the error degree in calculating the difference in time of ultrasonic signal transmission in and counter the direction of the flow of the controlled medium in the pipeline.
The reason for impossibility of achieving the above-described technical result lies in the fact that the traditional method used when determining the difference between the measured time values of ultrasonic signal transmission in and counter the direction of the flow of the controlled medium in the pipeline is mostly based on comparing these measured values and obtaining the difference thereof and does not provide for measuring this difference fairly enough, which eventually does not allow the accurate computation of the volume flow rate of the controlled medium in the pipeline, whereas no proper efforts were made at finding alternative solutions.
Considering the prior art solutions and analyzing them it can be concluded that the objective of developing equipment for measuring the volume flow rate of the controlled medium in a pipeline, which ensures greater accuracy, remains topical.